Top die shoe auxiliary restraint

ABSTRACT

A top die shoe auxiliary restraint which is utilized in conjunction with a primary clamping arrangement to secure the top die shoe to the ram of a press. The auxiliary restraint is designed so as to prevent dropping of the top die shoe from the ram upon loosening of the primary clamping arrangement. In the preferred form, the auxiliary restraint comprises a channel in a clamping member which is adapted to receive a headed member secured to the top die shoe.

United States Patent 1 1 1111 3,866,459

Zepp et al. Feb. 18, 1975 TOP DIE SHOE AUXILIARY RESTRAINT 3,563,560 2/1971 JOhIlSOn 83/698 {75] Inventors: Philip H Zepp; Lawrence R 3,640,170 2/1972 13131111611 83/698 Mancini, both of North Canton, FOREIGN PATENTS OR APPLICATIONS Ohio 604,809 7/1943 011111 1311111111 72 456 [73] Assignee: The Hoover Company, North Canton Ohio Przmary Examiner-C. W. Lzmham Assistant Examiner-Gene P. Crosby [22] Filed: Feb. 8, 1974 [21] Appl. N0.: 440,681 [57] ABSTRACT A top die shoe auxiliary restraint which is utilized in conjunction with a primary clamping arrangement to [52] US. Cl. 72/462 51 1111. c1 B21 j 13/02 Seeure the top (he Shoe the efe Prese The [58] Field of Search 72/462 470 83/698 iliary restraint is designed so as to prevent dropping of 5 106/1316 the top die shoe from the ram upon loosening of the primary clamping arrangement. In the preferred form, [56] References Cited the auxiliary restraint comprises a channel in a clamp- UNITED STATES PATENTS ing member which is adapted to receive a headed l 890 N5 17/1932 Altvater 83/637 member secured to the top die shoe. 2:445:574 7/1948 0111116111 83/637 5 Claims, 5 Drawing Figures PATENTEB FEB 1 8 I975 SHEET 10F 2 TOP DIE SHOE AUXILIARY RESTRAINT BACKGROUND OF THE INVENTION This invention relates to presses and the method of securing a die shoe of a die set to a part of the press. While the present invention could be utilized to secure the bottom die shoe to the bolster of a press, it is more particularly suited for securing the top die shoe to the ram of the press.

In the past it has been quite common to utilize a single means of securing the top die shoe to the ram of the press. In many cases, this has been a frictional securing means which is held in place by a threaded member. If the threaded member were to loosen, the friction resistant would be lost, thus causing the top die shoe to fall.

SUMMARY OF THE INVENTION The present invention is directed to a new and improved securing means for fastening the top die shoe to the ram of a press. For purposes of this specification, the ram means the upper part of the press, whether movable or stationary, to which the top die set member is secured. The present invention may also be used to secure the bottom die shoe to the bolster or bottom member of a press, but is particularly adapted for the top die shoe to ram securing means.

The present invention more particularly is directed to an auxiliary restraint utilized to prevent relative vertical movement between the top die shoe and the ram if the primary securing means fails.

Another aspect of the invention is to utilize a single member for both the primary securing means and also as a part of the auxiliary restraint for securing the top die shoe to the ram of a press.

A further aspect of the invention is to use the single securing means for both the primary and the auxiliary restraint, the single securing means being of such form that its removal releases both the primary restraint and the auxiliary restraint to facilitate removing the top die shoe from the press.

BRIEF DESCRIPTION OF THE DRAWINGS The invention, together with its construction and method of operation and along with other objects and advantages thereof, is illustrated more or less diagrammatically in the drawings, in which;

FIG. 1 is a perspective view ofa press which includes a die set which provides the environment of this inventron;

FIG. 2 is a fragmentary horizontal section taken along lines 22 of FIG. 1 showing a prior art clamp cap and shank relationship;

FIG. 3 is an enlarged front view of the press of FIG. 1 showing the die set and the clamp cap of the present invention;

FIG. 4 is a cross section through lines 4-4 of FIG. 3; and

FIG. 5 is an enlarged cross section taken along lines 5-5 of FIG. 4.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, FIG. 1 illustrates the environment of the invention which includes a press 1 which contains a die set 2. The die set 2 has a top die shoe or punch holder 3 and a bottom die shoe or die holder 5. The top die shoe 3 is connected to an upper part 4 of the press, for the purposes of this specification referred to as a ram, which generally is movable, while the bottom die shoe 5 is connected to a lower part 6 located on the bed of the press 1, which for purposes of this specification is referred to as a bolster, and which is generally but not always stationary.

The die set 2 not only includes the top and bottom die shoes 3 and 5 but may also include guide posts 7 which may or may not have biasing springs to separate top and bottom die shoes. The top die shoe generally has a bore or guide to receive the top of the posts 7 to allow reciprocation of the top die shoe. Generally, the top and bottom die shoes locate a punch 8 and a die 9 which cooperate to perform the desired metal working operation. The punch 8 and die 9 are secured to the top and bottom die shoes 3 and 5 respectively by means, not shown for clarity purposes, well known in the art. The specific form of the die set is not a part of the present invention and any die set may be utilized.

FIG. 2 discloses a common primary top die shoe securing means old in the art. A shank securing means or clamp cap 10 is used to retain the top die shoe 3 to the ram 4 by means of a frictional gripping with respect to a shank 11 which is structurally integral with the top die shoe 3, such as by a threaded connection, press fit, or welding. In this form of clamping arrangement, the ram 4 is provided with a pair of generally horizontally extending threaded studs 12 while the clamp cap 10 is provided with generally horizontally extending bores 13 which cooperate with studs 12 to locate the clamp cap 10 with respect to a recess in the lower front of the ram 4.

It is general practice to locate the die set 2 on the bolster 6 of the press with the ram 4 raised and the shank 11 in alignment with a vertical pocket 14 of ram 4. At this time the clamp cap 10 is not located on the studs 12. The ram 4 is then lowered so that the vertical pocket 14 receives the vertically extending shank 11 of the top die shoe 3. The bores 13 of clamp cap 10 are now aligned with the studs 12 and the clamp cap 10 is moved horizontally to bring the V-groove 16 into frictional abutment with the shank 11. A pair of nuts 15 are now positioned on the studs 12 and properly tightened so as to maintain frictional engagement between the V-groove 16 of the clamp cap 10 and the shank 11 so that the ram 4 can now be reciprocated vertically without the top die shoe 3 being separated therefrom.

The present invention is directed to an auxiliary restraint which is used in addition to the primary securing means of the top die shoe. The auxiliary restraint may be used with other primary securing means, but the primary securing means described above is the preferred form used in combination with the auxiliary restraint now to be described.

In the present invention the clamp cap 10 not only provides the primary securing means but also provides one part of an auxiliary restraint. In the preferred form, a T-shaped channel 20 is provided along the lower edge of the clamp cap 10 and extends inwardly from the front face thereof. This T-shaped channel 20 receives the other part of the auxiliary restraint which in the preferred form consists of a T-headed washer 21 which is of the same general size but slightly smaller than the T-shaped channel 20. This T-headed washer 21 has a counter-sunk vertical bore 22 which receives a screw 23. The head of the screw 23 is received in the counter sunk portion of the bore 22 so that the head of the screw 23 is flush or recessed with the top edge of the T-headed washer 21. The top die shoe 3 is provided with a vertical threaded bore 24 which underlies the channel 20 of the clamp cap when the die set 2 is properly placed with the press 1.

To secure the die set 2 in the press 1, the T-headed washer 21 is secured to the top face of the top die shoe 3 by means of the screw 23 and the die set 2 is now positioned in the press 1 with the ram 4 in its upper position. The ram 4 is lowered so as to receive the shank 11 in pocket 14 and abut the top face of the top die shoe 3. Clamp cap 10 is now positioned so that bores 13 are in alignment with the horizontal studs 12 to also bring the horizontal channel into alignment with the T- shaped washer 21 now secured to the top die shoe 3. The clamp cap 10 is now moved inward so that V- groove 16 frictionally abuts shank 11 and the T-shaped channel 20 captures the T-headed washer 21. The clamp cap 10 is held in this position by the nuts 15. With the clamp cap 10 in this position, the top top shoe 3 is now secured to ram 4 by means of the frictional engagement between the clamp cap 10 and the shank 11 and also the capturing of the head of the T-headed washer 21 within the channel 20.

It should be noted that even if the nuts should loosen or be completely removed from the stud 12, and thus the clamp cap 10 would release its frictional engagement with shank 11, the top die shoe 3 still cannot fall due to the captured relationship between the T- headed washer 21 secured to the top die shoe and the channel 20.

It should also be noted that when the clamp cap 10 is properly positioned, the screw 23 will not back out of the T-headed washer 21 due to the relative size relationship of the channel to the T-headed washer and headed screw 23. The head of the screw 23 is flush with the top of T-headed washer 21 and the top surface of.

quirement being that the cooperating parts are of such size and shape so as to prevent relative vertical movement, and thus restrain the top die shoe from dropping if the frictional engagement with the shank 11 is lost as described above.

It is also desirable that the part of the clamp cap used for the auxiliary restraint be a channel or generally parallel to the studs 12. Thus, the clamp cap 10 can be slid onto the studs 12 and also capture the other part of the auxiliary restraint secured to the top die shoe 3 at the same time for easy single operation assembly.

We claim:

1. A top die shoe securing means comprising an upper press part having a shank-receiving pocket, 21 die shoe having a shank adapted to be received in said pocket, a shank-securing means adapted to secure said shank in said pocket, said shank-securing means being restrained against movement with respect to said upper press part parallel to said shank, and auxiliary retaining means restricting movement of said die shoe with respect to said shank-securing means parallel to said shank, said auxiliary retaining means comprising means carried in part by said shank-securing means and means carried in part by said top die shoe which are movable relative to each other perpendicularly to said shank.

2. A top die shoe securing means comprising a ram having a vertical pocket, a top die shoe having an upwardly extending shank adapted to be received in said pocket, a clamp cap being secured against vertical movement with respect to said ram and being adapted to be horizontally movable to a locked position whereby said shank is secured in said pocket to prevent vertical movement of said top die shoe with respect to said ram, said clamp cap having a horizontal channel, a top die shoe retaining member secured to said top die shoe and being adapted to be horizontally movable in said channel and vertically restrained within said channel whereby said top die shoe is further restrained against vertical movement with respect to said ram when said retaining member is received in said channel.

3. The top die shoe securing means of claim 2 wherein said channel is T-shaped and said retaining member includes a Theaded member adapted to be received in said T-shaped channel.

4. The top die shoe securing means of claim 3 wherein said T-headed member includes a bore which receives a headed fastening member which secures said T-headed member to said top die shoe.

5. The top die shoe securing means of claim 4 wherein a portion of said clamp cap is in closely spaced relation with respect to said T-headed member when the latter is received in said T-shaped channel to prevent removal of said headed fastening means from said bore of said T-headed member. 

1. A top die shoe securing means comprising an upper press part having a shank-receiving pocket, a die shoe having a shank adapted to be received in said pocket, a shank-securing means adapted to secure said shank in said pocket, said shank-securing means being restrained against movement with respect to said upper press part parallel to said shank, and auxiliary retaining means restricting movement of said die shoe with respect to said shank-securing means parallel to said shank, said auxiliary retaining means comprising means carried in part by said shanksecuring means and means carried in part by said top die shoe which are movable relative to each other perpendicularly to said shank.
 2. A top die shoe securing means comprising a ram having a vertical pocket, a top die shoe having an upwardly extending shank adapted to be received in said pocket, a clamp cap being secured against vertical movement with respect to said ram and being adapted to be horizontally movable to a locked position whereby said shank is secured in said pocket to prevent vertical movement of said top die shoe with respect to said ram, said clamp cap having a horizontal channel, a top die shoe retaining member secured to said top die shoe and being adapted to be horizontally movable in said channel and vertically restrained within said channel whereby said top die shoe is further restrained against vertical movement with respect to said ram when said retaining member is received in said channel.
 3. The top die shoe securing means of claim 2 Wherein said channel is T-shaped and said retaining member includes a T-headed member adapted to be received in said T-shaped channel.
 4. The top die shoe securing means of claim 3 wherein said T-headed member includes a bore which receives a headed fastening member which secures said T-headed member to said top die shoe.
 5. The top die shoe securing means of claim 4 wherein a portion of said clamp cap is in closely spaced relation with respect to said T-headed member when the latter is received in said T-shaped channel to prevent removal of said headed fastening means from said bore of said T-headed member. 